Mirror petal modulator



Oct. 1, 1963 c. A. GLENN MIRROR PETAL MODULATOR Filed Nov. 16, 1960 INVENTOP CHARLES A. GLENN AGENT United States 3,145,486 MIRROR FETAL MODULATOR Charles A. Glenn, West Hartford, Conn., assignors to United Aircraft Corporation, East Hartford, Conn., a corporation of Delaware Filed Nov. 16, 1968, Ser. No. 69,747 6 Claims. (Cl. 126-270) This invention relates to reflector devices, and more particularly to means for controlling the amount of reflection from a reflector device. In some respects this invention is an improvement over the invention of Julius W. Tumavicus disclosed in United States application Serial No. 21,988 filed April 13, 1960, issued on November 20, 1962, as Patent No. 3,0645 34, which is assigned to the assignee in the present case.

In reflector devices of the type under consideration, a plurality of sectors are rotated from a closed position to an opened position to form a reflecting surface to reflect energy to or from an energy responsive device. In order to employ a reflector over a range of operating conditions or to adapt a reflector to serve a variety of requirements, it is necessary to control the amount of reflection and hence the power output of the energy responsive device. Also, it is desirable that the control mechanism be simple and be=separate from the main actuating mechanism to avoid complicating that mechanism.

One situation in which such a reflector device is applicable is a solar heater for a space vehicle. The reflector is in the form of a parabola of revolution, and a boiler is placed adjacent to the focal point of the parabola to receive reflected sun rays. In order to prevent overheating of the boiler or to vary the output from the boiler, a means must be provided for controlling the amount of reflection from the reflector to the boiler.

Accordingly, one feature of this invention is a control mechanism for a reflector made up of sectors rotatable about a first axis to assume an operating condition wherein reflection control is achieved by rotating one or more of the sectors about a second axis.

Another feature of this invention is a control mechanism for a reflector made up of rotatable sectors wherein the desired amount of reflection can be selected and maintained.

Still another feature of this invention is a control mechanism for a reflector made up of rotatable sectors wherein the control mechanism is separated from the mechanism used to rotate the reflectors. I

Still another feature of this inventionis a control mechanism for a reflector made up of rotatable sectors wherein some of the sectors are removed from the operating position and caused to cover adjacent sectors in response to a signal from a device in communication with the reflector.

Other features and advantages will be apparent from the specification and claims, and from the accompanying drawings which illustrate an embodiment of the invention.

FIG. 1 is a view showing the reflector in its extended or operating position, with a phantom showing of the closed position.

FIG. 2 is a view of one of the reflector sectors.

FIG. 3 is a side view of the reflector sector of FIG. 2.

FIG. 4 shows the mechanism for taking a reflector sector out of focus.

FIG. 5 shows a mechanism for simultaneously taking a plurality of reflector sectors out of focus.

Referring to FIG. 1, the reflector unit corresponds in general to the reflector disclosed in above-identified application Serial No. 21,988, now Patent No. 3,064,534, and includes a base having an angled portion 12. Angled portion 12 contains a plurality of holes 14 disposed in a circle around the circumference of base '10.

These holes are angled both with respect to the surface of portion 12 and the center line of base 10 so that the ms of each hole is skewed with respect to the center line of base it A shaft 16 having a finger 18 extending therefrom is mounted to each hole 14-, and each finger 13 is attached to a concave reflector sector 20 of parabolic curvature. Each hole 1-4 defines the axis of rotation of the sector 2% associated therewith as the sectors move from the closed to the extended position. In the operating or extended position, reflector sectors 2% cooperate to form a parabolic surface of revolution, and a boiler 22 supported by struts 23 attached to base It is positioned at the focal point of the parabola.

FIGS. 2 and 3 show a bent portion 24 extending between shaft 16 and finger 18 attached to reflector sector 20, the purpose of which will be described hereinafter. However, in most of the reflector sectors, the shaft '16 extends directly to finger 13 at a compound angle. That. is, there is an angle A in the plan view and an angle B in the side view. A rod 26 having a ball 28 thereon extends from each shaft 16, and a cam 36 contacts each ball 28. In the closed position, reflector sectors 20 assume a position such that they are axial with the edges substantially along radial lines of base plate 10. Movement of cams 3% will cause reflector sectors 28" to move outward and downward to the extended position about axes of rotation defined by holes 14, the path of movement being determined by the compound angle A-B in conjunction with the angularity of holes 14. The actuation of cams 30 is not a part of the present invention, but can be accomplished by any convenient method such as the method disclosed in the above-identified application Serial No. 21,988, now Patent No. 3,064,534.

In the extended position, reflector sectors 24] reflect sun rays to heat boiler 22. A means must be provided for moving one or more reflector sectors out of focus in order to prevent overheating of boiler 22. A temperature bulb 32 communicates with a bellows I.- through a fluid-filled line 36. Bellows 34 is attached to plate 37 which is fixed on base it), and bellows 34 is also attached to a plate 33. A sling 39 consisting of Wires 4i) which extend from plate 33 and merge to a single wire 4-1 extends to a pin 42 on reflector sectors 2%. A flexure pivot 43 consisting of two interlocking pieces of flexible material brazed together is interposed in bend 24. Any overheating of boiler 22 will expand bellows 34 and sling 35 will pull on reflector sector it to cause it to rotate about an axis defined by flexure pivot 43, which axis is different from the axis of rotation defined by hole 14. Reflector sector 2% will be moved out of focus to reduce the amount of sun ray energy being reflected to boiler 22 thereby reducing the temperature of boiler 22. It should be apparent that rotation of a reflector sector 20 out of focus in this manner will also cause a shading of an adjacent reflector sector so that the amount of reflection from two reflector sectors will actually be affected. A stop 44 is provided to limit the expansion of bellows 34, because after a certain amount of rotation of a reflector sector out of focus has occurred with the attendant covering of an adjacent sector, further rotation will only serve to uncover already covered portions of the adjacent section.

An additional means is provided to select the output level of boiler 22. A second temperature bulb 46 surrounded by heater 48 communicates with line 35 and bellows 34 through line 5%. Activation of heater 4%, indicating a reduced output requirement of boiler 22, will expand bellows 34 and sling 44 will pull on reflector sector 2% to cause it to rotate about the axis defined by flexure pivot 43. Reflector sector 21 will be moved out of focus to reduce the amount of sun my energy being reflected to boiler 22 thereby reducing the output of boiler 22. Of

course, as previously described, movement of reflector sector 20 out of focus in this manner will also cause a shading of an adjacent sector. After the desired amount of reflection is selected, the signal from bulb 32 will maintain the reflection and boiler output constant.

It is apparent that any number of reflector sectors can be rotated out of focus in the described manner, either by individual actuators of the type described or by a common actuator such as shown in FIG. 5.

In the mechanism shown in FIG. 5, parts corresponding to FIG. 4 are marked with a prime superscript. Bellows 34 is mounted on reflector plate and comm-unicates with fluid-filled line 36. Several wires or flexible metal strips 52 extend between plate 38' and plate 10, and wires 54 go from wires 52 to pins 42 on several reflector sectors '20, each wire 54 vgoing to a different pin 42. In this manner, expansion of fluid-filled bellows 3-6 will cause simultaneous rotation of several reflector sectors 20 out of focus.

It is to be understood that the invention is not limited to the specific embodiment herein illustrated and described but may be used in other ways without departure from its spirit as defined by the following claims.

I claim:

1. A reflector comprising: a plurality of reflector sectors disposed in side-by-side relation to define a surface having a focal point; at least one of said reflector sectors having a support including :a bend; a flexure element in said bend defining 'an axis of rotation; and means rotating said one reflector sector about said axis between a position which is in focus and a position out of focus and in overlapping shading relation with an adjacent reflector sector to vary the degree of radiation reflected toward said focal point, said means rotating said one reflector sector including an energy receiving device disposed at said focal point and responsive to radiation received at said focal point, said energy receiving device having an expansible member connected with said one reflector sector.

2. A reflector as defined in claim 1, in which said flexure element comprises a pair of interlocking pieces of flexible material.

' 3. A collapsible reflector, comprising: a plurality of rotatably mounted concave reflector sectors, each sector having a primary axis of rotation including a base and a plurality of shafts rotatably mounted in said base; means simultaneously rotating all of said sectors about said primary axes between a collapsed position and an extended position wherein said reflector sectors are disposed in side-by-side relation to form a surface of revolution having a focal point; at least one of said reflector sectors having a secondary axis of rotation including a bend in its shaft and a flexure element in said bend; and means rotating said one reflector sector about said axis between its extended position and a position out of focus and in overlapping shading relation with an adjacent reflector sector to vary the degree of radiation reflected toward said focal point. g

4. A reflector as defined in claim 3, in which said means rotating said one reflector sector includes an energy receiving device disposed at said focal point and responsive to radiation received at said focal point, said energy receiving device having an expansible member connected with said one reflector sector.

5 A reflector as defined in claim 3, in which said flexure element comprises a pair of interlocking pieces of flexible material.

6. In a reflector, a plurality of rotatably mounted reflector sectors, each sector having a primary axis of rotation, said reflector sectors forming a reflecting surface having a focal point, an energy receiving device located at said focal point, means simultaneously rotating all of said sectors about said primary axes, at least one of said reflector sectors having a secondary axis of rotation, and. independent means, including a sling attached to said one reflector sector and a bellows attached to said sling, said bellows being responsive to the temperature of said energy receiving device, for rotating said one :reflector sector about said secondary axis to vary the amount of energy transmission between said reflecting surface and said energy receiving device.

References Cited in the file of this patent UNITED STATES PATENTS 509,390 Paine NOV. 23, 1893 707,982 Taylor Aug. 26, 1902 1,339,304 Thompson May 4, 920 1,509,744 Wilson Sept. 23, 1924 1,951,404 Goddard Mar. 20, 1934 2,945,234 DriscOll July 12, 1960 3,064,534 Tu-mavicus Nov. 20, 1962 FOREIGN PATENTS 993,096 France July 18, 1951 r 

1. A REFLECTOR COMPRISING: A PLURALITY OF REFLECTOR SECTORS DISPOSED IN SIDE-BY-SIDE RELATION TO DEFINE A SURFACE HAVING A FOCAL POINT; AT LEAST ONE OF SAID REFLECTOR SECTORS HAVING A SUPPORT INCLUDING A BEND; A FLEXURE ELEMENT IN SAID BEND DEFINING AN AXIS OF ROTATION; AND MEANS ROTATING SAID ONE REFLECTOR SECTOR ABOUT SAID AXIS BETWEEN A POSITION WHICH IS IN FOCUS AND A POSITION OUT OF FOCUS AND IN OVERLAPPING SHADING RELATION WITH AN ADJACENT REFLECOR SECTOR TO VARY THE DEGREE OF RADIATION REFLECTED TOWARD SAID FOCAL POINT, SAID MEANS ROTATING SAID ONE REFLECTOR SECTOR INCLUDING AN ENERGY RECEIVING DEVICE DISPOSED AT SAID FOCAL POINT AND RESPONSIVE TO RADIATION RECEIVED AT SAID FOCAL POINT, SAID ENERGY RECEIVING DEVICE HAVING AN EXPANSIBLE MEMBER CONNECTED WITH SAID ONE REFLECTOR SECTOR. 